Moving stairway



J. D UNLOP MOVING STAIRWAY Nov. 10, 1936.

2 Sheets-Sheet l Filed- July 26, 1935 I NVENTOR James Dun/0,0

ATT NEY "Frill/ J. DUNLOP MOVING STAIRWAY Nov. 10, 1936.

Filed July 26, 1935 2 Sheets-Sheet INVENTOR Patented Nov. 10, 1936 UNITED STATES PATENT OFFICE MOVING STAIRWAY Application July 26, 1935, Serial No. 33,310

12 Claims.

My invention relates to moving stairways and more particularly to means for maintaining the step rollers and tracks of moving stairways free from dirt.

One object of my invention is to provide for keeping the various moving parts of a moving stairway in a clean condition at all times during their operation.

Another object is to provide automatic apparatus for cleaning the moving parts of moving stairways which may be easily and economically constructed, installed and maintained in operation.

A further object is to provide apparatus for cleaning stairways which shall be entirely automatic in operation and which shall require practically no care on the part of the stairway attendants.

More specifically, it is the object of my inven- 20 tion to provide apparatus which will automatically sweep from thejracks, from the step rollers which roll upon the tracks and from the step treads any dirt which may fall thereon.

Other objects of the invention will be obvious and appear hereinafter. For a clearer understanding of the invention reference may be had to the accompanying drawings in which:

Figure l is a view, in side elevation, of the lower landing portion of a moving stairway em- 30 bodying my invention.

Fig. 2 is a view taken on the lines IIII of Fig. 1.

Fig. 3 is a view taken on the line III-III of Fig. 1.

Fig. 4 is a top plan view of a portion of the stairway atthe lower landing.

Fig. 5 is a detailed view of a portion of one of the sprocket chains shown in Figs. 1 and 4.

Fig. 6 is a view taken on the line VI-VI of Fig. 5.

Fig. '7 is a view, in side elevation, of one of the inside track brushes shown in Fig. 1.

Fig. 8 is a view taken along the line VIII--VIII of Fig. 7.

Fig. 9 is a view, in rear end elevation, of the track brush shown in Fig. 7.

Fig. 10 is a view in side elevation of one of the outside track brushes shown in Fig. 2, and

Fig. 11 is a view taken along the line XI-XI of Fig. 10.

Referring more particularly to the drawings, I have illustrated the lower landing portion of a moving stairway (Figs. 1 and 4) as comprising an endless series of movable steps S disposed to be moved along two pair of upper tracks land 2,

and 3 and 4 and lower tracks 5 and 6 by a pair of gear chains 1 and 8 between an upper landing (not shown) and a lower landing Ill. The gear chains are supported at the lower landing by a pair of sprocket wheels H and I2.

The chain 1 comprises a plurality of outer links l4 and I5 (Figs/5 and 6), a plurality of inner links 16 and I! joined by a plurality of cross pins l3. Referring more particularly to Fig. 6, the pin la is constructed with its ends provided with grooved surfaces l9 upon which the ends of the outer links [4 and I5 may be mounted. The grooved surfaces l9 should be of such size that they will make what is known as a press fit with cooperating holes in the outer links M and I5 and thereby cause the pins and the links to freeze and turn or act as one body after the chain is assembled.

A bushing 2| is rotatably mounted upon the pin I81: and the inner links l6 and I! are mounted upon the ends thereof by means of a press fit so that the bushing freezes to the inner links and rotates with them upon the pin [8a. A chain roller 22 is rotatably mounted upon the bushing 2| for the purpose of engaging the sprocket wheel teeth as the chain operates over the sprocket wheel. The sprocket chain 8 is constructed in the same manner.

Each of the steps S comprises a frame 24, a step tread 25, a pair of leading rollers 26 and 21 (see Fig. 3) and a pair of trailing rollers 28 and v 29. The tread 25 may be made of any suitable material, preferably of molded fibrous material with a heat-hardened binder. The surface of the tread 25 is constructed with a plurality of grooves 30 which provide a plurality of cleats 3| on its upper surface. The grooves extend from the front to the rear of the step and may be of any suitable width so long as they are sufiiciently narrow to prevent the shoe heels of the passengers from entering therein.

The front rollers 26 and 21 are connected to the steps S by an axle 33, the outer ends of which extend through the chains 1 and 8, the rollers being mounted on the outer ends of the axle beyond the chain in any suitable manner. By this construction, the front rollers are disposed to travel along the track rails I and 4 and thereby aid in supporting the chains 1 and 8 as well as supporting the steps S. It will also be apparent that this connection of the axle 33 with the chains provides a means whereby the movement of the. chains is imparted to the steps so that operation of the chains causes the steps to be carried along the stairway. The rear rollers 28 and 20 are mounted upon the step by an axle 34 in position to roll along the track rails 2 and 3.

As the steps and chains approach the lower landing while being operated in the direction shown by the arrow 35, the front rollers leave the lower track rails 6 and are then left suspended in the air as the chains are carried around the sprocket wheels H and I2. The rear rollers 28 and 29 continue along the lower track rails which turn into a circular guard rail 31 running concentric with the lower landing sprocket wheels. leave the guard rail 31 and move along a circular track rail 38 mounted on the axle 39 of the sprocket wheels. As the steps continue their journey around the lower landing sprocket wheels, the rear rollers leave the circular tracks 38 and move upon the upper tracks 2 and 3. As the steps continue, the upper rollers complete their trip around the sprocket wheels and finally come into engagement with the upper track rails I and 4. The steps now travel to the upper landing (not shown) with their front rollers 26 and 21 upon the upper track rails and 4 and their rear rollers upon the track rear rails 2 and 3.

A frame 4| (only a portion of which is shown) is provided for supporting the stairway in its operating position. A combplate 42 is secured to the frame 4| at the lower landing ID to enable the stairway passengers to enter and leave the stairway.

In the operation of moving stairways, it is desirable to keep the stair treads and the various parts of the stairway as free from dirt as possible. However, in connection with the stair treads, it has been found desirable to clean out the grooves 30 but to leave the upper surfaces of the cleats 3| untouched except when they accumulate such an amount of dirt as makes it necessary to brush or otherwise clean them by hand. In practice it has been found that the ordinary accumulation of dust and grit on the top surfaces of the cleats aids the passengers in maintaining their footing and keeps them from slipping while they are making use of the stairway.

In accordance with my invention I have provided a brush for automatically cleaning the grooves in the step treads while leaving the dust on the cleats undisturbed. This means comprises a tread brush 44 (Figs. 1, 3 and 4) located at the lower landing and having its outer ends bolted or otherwise fastened to the side members 45 of the frame 4|. The tread brush is provided with a plurality of rows of bristles 46 so disposed on its under side that they sweep through the grooves 30 of the step treads as the steps are moved along the lower landing. The tread brush may be located at any suitable point, however, in the present instance it is shown as positioned at the rear of the combplate 42 and just ahead of the lower landing plate l0.

From the drawings, it will be apparent that as the steps are operated along their tracks by their gear chains, the bristles 46 of the tread brush will sweep through the grooves 30 in the treads and prevent the accumulating of dirt and dust therein. Inasmuch as the bristles 46 do not touch the top surfaces of the cleats 3|, the cleats will remain dusty and gritty, thus providing a safe step surface. At the same time, if any large pieces of dirt or fibres, etc., get across the cleats, the bristles will sweep them from the top of the cleats. Hence it will be seen that the brush will tend to keep the cleats clean to a certain: degree As the rear rollers start upwardly they' but will not clean them to such an extent as to cause them to become polished and smooth.

The rollers upon which the steps operate and by which they are guided along their tracks, have a tendency to pick up dirt from various sources and this dirt causes annoying effects when the rollers roll along the tracks. In order to automatieally sweep the dirt from the rollers during their operation, I have provided a novel pair of brushes 5!! and 5|. The brush 50 is bolted or otherwise secured to a portion 52 of the frame 4| in such manner that the face of the brush will engage each of the front rollers 26 on one side of the step as it passes around the roller landing. The brush 5| is disposed to cooperate with the brush 5!] and is mounted upon a member 54 of the frame 4| by means of a plurality of bolts 55. The face of the brush 5| is disposed opposite the face of the brush 50 and at such a distance therefrom that it will also engage the other side of each of the front rollers 26 as the steps move around the lower landing.

The brushes 50 and 5| must be so mounted that they will bear with unequal pressure upon the rollers 26. For instance, the brush 5!) may be mounted so that it will exert quite a pressure against the roller 26 and the brush 5| may be so mounted that it will bear lightly against the roller 26 as it passes. With this construction, as the roller 26 passes between the brushes, the friction between the brush 50 and the roller tends to cause the roller to rotate against the lighter brush 5| and this action causes the brush 5| to sweep the dirt and dust from the roller.

In some cases it may be desired to make the bristles of one brush thicker and heavier than the bristles in the other brush and in that manner secure the desired rotation of the rollers. In other brushes it may be desirable to combine the two effects; that is, to make the bristles of the brush 50 heavy and thick and set the brush close to the roller and to provide the brush 5| with bristles of lighter weight than the bristles of the brush 50 and also set the brush 5| so that it will bear more lightly against the rollers than the brush 50. In the construction shown in Fig. 1, both the positioning of the brushes and the weighting of the bristles are employed and the combination operates effectively to keep the rollers 26 free from dust and dirt as they pass along their trip, thus leaving them clean to enter the tracks and roll along the track rails with a minimum amount of noise and effort.

Although I have provided means for keeping the rollers clean, it is also desirable to provide automatic means for keeping the roller tracks clean and free from dirt. To accomplish this purpose in practicing my invention, I provide a left hand inner track brush 58, a right hand inner track brush 59, a left hand outer track brush 60 and a right hand outer track brush 6|.

Referring more particularly to Figs. 5 to 11, the brush 6| is shown as provided with a body member 62 having a central hub 63 and brush faces 64 and 65. The brush face 64 is provided with a plurality of bristles 66 and the brush face 65 a plurality of bristles 61. The brush is mounted on the chain 1 by a T-headed bolt 66 which passes through the bored out center 69 of the chain pin l8a. The T-head of the bolt 68 rests in a slot in the outer face of the brush body 62 so that the bolt and the brush remain in fixed relation to each other. The nut end of the oolt 68 extends through the pin Hill to have mounted upon it the track brush 59.

matted upon the track and slicked over by the The inner track brush comprises a body portion 12 provided with an upwardly projecting member I9 having a squared hole I6 in its center disposed to flt upon a squared portion 14 of the bolt 98. A nut 15 is provided for holding the bolt in position as it extends through the outer brush 6|, the bored out pin I 8a, and the hub 13 of the brush 59. As noted, the T-headed end of the bolt 68 disposed in the slot 19 of the outer brush SI and thesquared inner portion of the bolt disposed in the squared aperture 16 in the hub 13 cause the outer brush, the bolt and the inner brush to remain in a fixed relation to each other and prevent independent movement of any one of them. Thus it is seen that only one bolt is necessary for securing both the outer brush and the inner brush in their operative position on the drive chain.

The brush 6| is so designed that its bristles 65 will engage the upper guard rail 68 and its bristles 61 will engage the track rail 4 while the steps are traveling along the upper portion of the stairway. The brush 59 is so designed that its bristles 19 will sweep the track rail 3 as the steps move along the upper portion of the stairway.

In order to maintain the brushes GI and 69 in their correct position during the operation of the stairway, an extended arm or projecting member 90 is mounted on the front portion of the body I2 of the brush 59. The projecting member 80 is provided upon its free end with a yoke or U-shaped aperture 8| ofsuch size that it may be fitted over a portion of the front axle 53 when the brushes 59 and 6| are assembled and bolted together. The engagement of the arm 89 with the axle 53 prevents the brush 59 and also the brush 6| from rotating relative to the chain so that they will follow the movements of the chain as it operates the steps along the track and thus cause the brush 59 to sweep the track rail 3 and the brush 6i to sweep the guard rail 68 and also the upper track rail 4 as the steps move along the upper side of the stairway.

As the steps reach the end of their upper trip at the upper landing (not shown) they will round the upper landing and move down along the under side of the stairway, during which movement the brush 6| will sweep the lower track rail 6. However, by reason of the changed position of the steps while traveling on the under side of the stairway, the inner brush 59 will not engage any track surface during that portion of the trip.

The left-hand inner brush 58 and the left-hand outer brush 60 are constructed and operated in practically the same way as the inner brush 59 and the outer brush 6| except that they are constructed for attachment to the opposite or left-hand side of the stairway.

In practice, it is usually found advisable to employ what are known as China bristles in the various brushes, particularly in the inner and the outer track brushes. However, in some cases it has been found that the use of China bristles tends to let sticky dirt of a certain nature accumulate in spots on the track rails, the brush tending to slide over such small accumulations of dirt and polish them without removing them. To avoid this, I place a second brush 59a ahead of the brush 59 and likewise a second brush ahead of the brush 8|. The brush 59a is the counterpart of brush 6i but is provided with steel wire 83 instead of China bristles. The use of the steel wire breaks up any grit which may have become China bristle brush. In practice, it is usually sumcient to connect to each chain only one brush for each track rail except in cases where dirt is very heavy. In such instances, one China bristle brush and one steel wire brush for each track will usually be found more effective.

By reason of the foregoing construction, it will be seen that I have provided automatic means responsive to operation of the gear chains for simultaneously sweeping dirt from the stair treads, from the step rollers and from the track rails as long as the stairway is in operation, thus keeping its various parts clean and causing the stairway to operate with ease and without producing such noise as usually follows operation of dirty steps over dirty tracks.

Although I have illustrated and described only one specific embodiment of my invention, it is to be understood that many changes therein and many modifications thereof may be made without departing from the spirit and scope of the invention.

I claim as my invention:

1. In a moving stairway, a frame, a plurality of tracks mounted upon the frame, a pluralityof steps, a plurality of rollers mounted on the steps for guiding them along the tracks, a brush mounted on the frame with its brush surface disposed to engage the tread surface of each step as the step passes the brush, a plurality of brushes mounted on the frame with their brush surfaces disposed to engage the rollers as the steps pass, a pair of endless gear chains for moving the steps along the tracks and causing the tread brush and the roller brushes to sweep the treads and the rollers, and a plurality of brushes connected to the chains with their brush surfaces disposed to engage and sweep the tracks as the chains move along the tracks.

2. In a moving stairway, a frame, a track mounted on the frame, a plurality of steps, a plurality of rollers mounted on the steps for guiding them along the track, a brush mounted on the frame with its brush surface disposed to engage the tread of each step as the step passes the brush, a pair of cooperating brushes mounted on the frame with their brush surfaces disposed opposite to each other and in position to engage a roller on each step as the steps pass the brushes,

a chain for moving the steps along the track and causing the tread brush and the roller brushes to sweep the treads and the rollers, and a brush connected to the chain with its brush surface disposed to engage and sweep the track in accordance with the movement of the chain in operating the steps.

3. In a moving stairway, a frame, a track mounted on the frame, a plurality of steps, each of said steps having a tread provided with a plurality of grooves, a brush mounted on the frame with its brush surface disposed to engage only the grooves in each tread of each step as it passes the brush, and a chain for moving the steps over the track and causing the brush to sweep only the grooves of the treads of the steps.

4. In a moving stairway, a frame, a track mounted on the frame, a plurality of steps provided with grooved treads, a brush having its outer ends mounted on the side members of the frame at the lower landing of the stairway, said brush being provided with rows of bristles disposed to engage only the cooperating grooves in the tread of each step as it passes the brush, and a chain for moving the steps over the track and causing the brush to sweep the-treads of the steps.

5. In a moving stairway, a frame. a track mounted on the frame, a plurality of steps, a track brush, means for pivotally mounting the brush on one portion of the chain, and means for connecting one end of the brush to another portion of the chain to maintain the brush surface of the brush in engagement with the track and sweep it free from dirt as the chain operates the steps along the track.

6. In a moving stairway, a frame, a track mounted onthe frame, a plurality of steps, a plurality of rollers mounted on the steps for guiding them along the track, a plurality of front axles, one for each step, for mounting the front rollers of the steps thereon, said axles extending through said chain, a brush pivotally mounted on a portion of the chain between the axles, and means for connecting one end of said brush to the front axle of the step adjacent to the position of the brush, whereby the face of the brush will, engage the track and sweep it as the chain operates the steps along the track.

'7. In a moving stairway, a frame, a track mounted on the frame, a plurality of steps, a plurality of rollers mounted on the steps for guiding them along the track, a plurality of front axles, one for each step, for mounting the front rollers of the steps thereon, said axles extending through said chain, abrush pivotally mounted on a portion of the chain between the axles, an arm on the brush having a recessed portion disposed to embrace the front axle of the step adjacent to the position of the brush, whereby the face of the brush will engage the track and sweep it as the chain operates the steps along the track.

8. A brush for the tracks of a moving stairway comprising a body, a plurality of brush bristles disposed on one face thereof, a projecting member on the central portion of said body, said member being provided with an aperture for pivotally connecting the brush to a portion of a moving stairway chain, and an arm disposed on one end of said body, said arm having a recessed surface at its outer end for engaging another portion of the moving stairway to control rotation of the brush after it is pivotally mounted in position on the chain.

9. In a moving stairway, a track, a plurality of steps, a plurality of rollers mounted on the steps for guiding them along the track, a chain comprising a plurality of links and pins for moving the steps along the tracks, a bolt disposed through one of the pins, said bolt having a T-head on its one end and a non-cylindrical portion on its other end, a track brush disposed on the T-head end of the bolt at one side of the chain, a second track brush rigidly mounted on the non-cylindrical portion of the bolt at the other side of the chain, and a projecting member disposed on one end of one of the brushes for connection to another track pin to control rotation of both brushes while in operation and cause their brush faces to sweep the tracks as the chains move the steps along the tracks.

10. In a moving stairway having a plurality of steps operated along a plurality of tracks by a chain, a T-headed bolt disposed through the chain, said bolt having a shaft with a non-cylindrical portion, an outer track brush mounted on the T-headed end of the bolt with a cooperating slot for the T-head to cause the brush to turn with the pin, and an inner track brush mounted on the non-cylindrical portion of the bolt at the side of the chain opposite to the outer track brush, said inner track brush having its brush face disposed to engage the inner track, a projecting member disposed on the end of the inner brush, and means for connecting the outer end of the projecting member to an adjacent portion of the chain to prevent rotation of the brushes and bolt beyond the normal rotation due to the operation of the chain.

11. In a moving stairway having a plurality of steps operated over a track by a chain, a frame for supporting the track, a plurality of brushes disposed with their brush faces facing each other to engage the rollers on the step as the steps are moved along by the chain, and means for mounting the brushes with the pressure of the one brush greater than the pressure of the other brush against the rollers whereby the one brush causes the roller to rotate against the other brush to be swept free of dirt.

12. In a moving stairway having a plurality of steps operated over a track by a chain, a frame for supporting the track, a plurality of brushes disposed with their brush faces facing each other to engage the rollers on the step as the steps are moved along by the chain, the bristles in the one brush being heavier than those in the other brush whereby the heavy bristles of the one brush frictionally engage the rollers and cause them to rotate against the lighter bristles of the other brush as they are moved by the chain and are thereby swept free of dirt.

JAMES DUNLOP. 

